TRP DHR Evo Brakes Explained

Words by Drew Rohde | Photos by Cole Gregg
Video by Brian Niles/Treeline Cinematics

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TRP has over 20 years-experience building high-performance brakes. In 2016, they upped the ante and began working with World Cup Champion Aaron Gwin, and while he was impressed with the initial performance, he had a list of improvements that he believed would create the best brakes on the market. TRP took those impressions and requirements from the World’s fastest rider and have been improving year after year. We’ve also had the opportunity to review both the TRP G-Spec Quadiem and the more affordable TRP G-Spec Slate brakes in the past and had similar findings to others. While TRP has been lauded for their quality construction, great modulation, and constant overall braking feel, they knew that they were missing one major ingredient in the perfect brake recipe. For that reason the new TRP DHR Evo gets a major overhaul and looks to build on the pedigree of already impressive brakes by adding what, until now, has been missing: more power.

TRP DHR EVO DESIGN AND DEVELOPMENT
Bikes are getting faster, wheels are getting bigger, and for TRP, those gains came without any notable changes to their brake offerings. Not surprisingly, the technology that was adequate then, simply won’t hold its own with today’s rider needs. With the emergence of 29er DH bikes, hard charging enduro rigs and the booming eMTB market, it became increasingly clear to the design team that a new, outside the box way of thinking would be needed to make a brake that could slow down today’s fastest riders. To let them rip trails like there’s no tomorrow, they needed bigger and badder. Enter: the TRP DHR Evo.

The new DHR Evo brake was a complete overhaul of the platform, and updates included many firsts for TRP as a brake manufacturer. Most notably, it is the first brake system to use thicker 2.3-millimeter rotors and a matching oversized caliper. Simply put, this is to handle the greater amount of heat generated as larger wheels, modern geometry, efficient suspension platforms and E power become the norm.

The inspiration for the dramatic redesign on the new TRP DHR EVO brake came from feedback they were getting from their athletes, teams, customers and yes, even us media hacks. According to TRP, the previous generation DHR brake was extremely reliable, but underpowered. TRP led a six-month performance overhaul with intense feedback from their team riders. Changes that came from this R&D process were many and vital to the design of the new brakes.

First off TRP developed a new formula for their mineral oil that has a much higher boiling point. Previous generations of mineral oil had a boiling point of 180 degrees Celsius but TRP’s new oil can withstand heat up to 230 degrees Celsius before boiling. This is a big jump in heat management and will undoubtedly improve lever feel on extended downhills.

TRP also took advantage of their ability to completely control their own manufacturing process by changing the formula of their resin brake pads. Although they wouldn’t disclose all their secrets to us, they explained a bit more in the interview below.

In sticking with the heat management theme, a new oil flow design in the caliper helps reduce heat pools, which keeps the brake performing stronger, longer. The way the oil flows and moves through the redesigned caliper offers increased efficiency, power and isolates itself from heat better.

IF YOU’D LIKE TO KNOW MORE ABOUT WHAT ELSE THE CREW AT TRP DID TO CREATE THEIR MOST POWERFUL AND REVOLUTIONARY BRAKE YET, CHECK OUT THE INTERVIEW BELOW.

HOW SPECIFICALLY DID YOU GET THE INCREASE IN POWER ON THE NEW DHR EVO?
TRP: With the utilization of our new 9-millimeter piston we have developed a new leverage ratio increasing our overall laboratory tested power by 62%. Obviously, lab numbers involve little variables so on the trail does it feel like 62%? Not quite in my book, but I can confidently say after riding the EVO and the feedback we have gotten from our other test riders, our overall power on the trail has gone up by about 25%.

To give all this power a home, we have focused on the 40 N pressure mark. This is smack in the middle of the norm 0-80 N pressure test and is what we refer to as the sweet spot. This is the spot that we have found riders start to initiate heavier braking, we have achieved a massive increase in power over the competition. This directly relates to riders not having to pull the lever as hard on steep downhills, saving those forearms. The emergency stop has also been addressed compared to the previous DHR there is a much steeper ramp in that 70-80 N pull range.

WHY DID YOU GO WITH 2.3MM ROTORS? HOW MUCH OF A DIFFERENCE DO THEY MAKE IN MANAGING HEAT?
TRP: We decided to run with 2.3 mm rotors because of the increased stability in all aspects. They have an 8% increase in heat capacity, a 47% increase in lateral stiffness which allows us to push the diameter of our rotors up to 223mm. Commencal 100% rider Thomas Estaques says it best, “Bikes and speeds are increasing each year, so if frame and suspensions are changing, you have to change the brakes, wheels, and other parts. It’s the logical path to follow. We were riding 200mm/180mm when we raced on 26-inch wheels, everybody rides 203mm with 27.5”, so it makes sense to have bigger 223/2.3mm rotors with 29inch wheels.”

With 2.3/223 mm rotors, there is more surface area to heat up making it more difficult for heat pools to form and impact the overall performance of the system.

HOW MUCH MORE DO THEY RESIST WARPING?
TRP: The 2.3mm rotors resist warping due to heat up to 47% more than standard thickness (1.8mm) rotors. This 0.5mm increase seems small on paper, but in the TRP R&D Labs, the result is almost doubling the resistance to warping.

WHAT CHANGES HAVE BEEN MADE TO THE RESIN PAD MATERIAL?
TRP: The resin pad material is a completely new formula for this year. Because we have complete control over the manufacturing process our pads, small and decisive changes can be implemented overnight. While the exact changes are not able to be specified, if used correctly, resin material can form smaller and more uniform pores than a full sintered metallic pad. This allows more surface area to contact the rotor and less air volume for heat to travel through. This brings a stronger initial bite and more consistent braking feel throughout the entire contact. Along with this, resin material is naturally easier to bed in and is much quieter on the trail, which is why we have poured over this development and increased their performance.

WHAT IS DIFFERENT ABOUT THE NEW MINERAL OIL THAT GIVES IT A HIGHER BOILING POINT AND DECREASED VISCOSITY?
TRP: We have worked on tweaking the chemical composition of our mineral oil and after rounds of development and tests, we have achieved a boiling point that is increased from 180 degrees Celsius to 230 degrees Celsius. A notable and necessary increase to prevent brake fade. Along with the increase in boiling point, we were able to refine and distil our composition to decrease its overall viscosity. Think of Aunt Jemima compared to pure maple syrup.

THE EXCITEMENT OF NEW BRAKES OFTEN COMES WITH THE PAIN OF INSTALLATION. OUR INSTALLATION WAS PRETTY EASY. WHAT DOES TRP DO TO HELP GET RIDERS ON THE TRAIL FASTER?
TRP: TRP brakes come pre-bled from the factory but split apart at the lever, this allows you to route the hose through the frame and cut it to length. Typically when setting up brakes you have to disconnect the line from the lever before measuring it and cutting it, during this process you end up losing a little fluid from the lever. With the Easy Plug System it’s easy to route and mark your line, then take the lever off keeping it up right and connecting the hose helping to eliminate fluid loss. If you happen to allow a little air in the system you can easily get it out by performing a basic lever purge.

BY HAVING 5MM HOSES, WE WOULD IMAGINE THAT OIL VOLUME IS (EVER SO SLIGHTLY) DECREASED IN THE NEW BRAKES. IS IT A NOTICEABLE AMOUNT? WAS THIS JUST TO HELP INCREASE HYDRAULIC LINE PRESSURE OR IS THERE MORE BEHIND THE CHANGE?
TRP: This year we transitioned all TRP products from 5.5mm hose to 5.0mm hose. This slightly decreases the oil volume in the hoses and coupled with our new mineral oil, provides a smoother actuation of the lever. This volume change in the hose is not noticeable in terms of heat management because it is not directly taking the heat. The most noticeable heat management change is in the caliper, where the new oil routing deposits more volume to the pistons making it harder to heat the system up. Realistically, the main drive to go with 5-millimeter hose was to increase the stiffness of the lines to provide better hydraulic transfer of power and to make it easier to internally route our lines in carbon frames.

ARE THERE ANY DIFFERENCES BETWEEN THE DHR EVO AND EBIKE BRAKE?
TRP: The only difference between the DHR EVO and E-brake is the color treatment and lever design, which includes the increased leverage ratio. This deceases overall cost to the customer while still providing class leading heat management for those heavier frames and larger wheels.